Polyaniline doping

Fig. 1. (a) Comparison of normalised electrical conductivity of individual MWCNTs (Langer 96 [17], Ebbesen [18]) and bundles of MWCNTs (Langer 94 [19], Song [20]). (b) Temperature dependence of resistivity of different forms (ropes and mats) of SWCNTs [21], and chemically doped conducting polymers, PAc (FeClj-doped polyacetylene [22]) and PAni (camphor sulfonic acid-doped polyaniline [2. ]) [24]. 

HPA-composite catalysts have also been studied for ORR.166 A conducting polymer and HPA were combined to form the 12-phosphormolibdic acid-doped polyaniline-V202 composite. The composite showed improved activity over the conducting polymer alone in a weak acid solution. 

Conducting polymers such as PEDOT PSS, doped polyaniline or polypyrrole, and... 

Conducting Polymers, PEDOT-PSS, Doped Polyaniline and Polypyrrole... 

Both the imine and the secondary amine nitrogens in polyaniline can be protonated by weak carboxylic acids of different pK values. Solid layers prepared from such doped polyanilines have different selectivity for interaction with gases. It is partially derived from the interaction of the analyte with the doping anion. 

Implicit in this equation is the assumption of constancy of the selectivity coefficient K, and the assumption of constancy of the term Vq. Those assumptions put this otherwise useful equation in the category of empirical relationships, the same as the Nikolskij-Eisenman equation. An example of such a response is shown in Fig. 6.36 in which WF CHEMFET with doped polyaniline/camphorsulfonic/ionic liquid gate was exposed to stepwise changes of ammonia concentration. In this case ammonia acts as an electron donor, thus lowering the work function of the selective layer. The value of 5g determined from the slope of (6.101) was found to be 0.6. 

Title Method of Making Novel Water-Soluble and Self-doped Polyaniline Graft Copolymers... 

Preparation of Self-doped Polyaniline Graft Copolymer... 

Preparation of a Self-supported and Drawable Film of Doped Polyaniline... 

Nanotubes using lignosulfonic acid-doped polyaniline were prepared by Vis-wanathan [2]. 

Hydrochloric acid as well as camphor sulfonic acid doped polyaniline prepared in chloroform often have [59] log a proportional to T as expected for quasi-one-dimensional variable range hopping, Equations (3) and (4). Generally, the higher conductivity samples have a weaker temperature dependence at low temperatures (Tq 700-1000 K for T<80 K), and lower conductivity samples a stronger temperature dependence (To 4000 K). The smaller Tq for the more highly conducting samples has been associated with weaker localization due to improved intrachain and interchain order. 

Figure 7 Calculated frequency dependence of the real part of the dielectric constant versus frequency for an array of quantum dots connected by one-dimensional wires (from Ref. 57). The inset presents the measured frequency dependent dielectric constant for four different samples of HCSA doped polyaniline of differing conductivities (from Refs 44...

Figure 8 Thickness dependence of total shielding efficiency (SET) of highly conducting polymers (A) stretched heavily iodine doped Tsukamoto polyacetylene, (B) camphor sulfonic acid doped polyaniline cast from m-cresol solvent, (C) PFg doped polypyrrole.

Transparent conducting polymers are of interest [66]. A number of these doped conducting polymers have been prepared as thin conductive films. It was shown that the optical window for doped polyaniline and other polymers can be tuned through control of processing conditions [67]. 

The basic structure of a typical dc-biased bilayer OLED is shown in Figure 1.5. The first layer above the glass substrate is a transparent conducting anode, typically indium tin oxide (ITO). Flexible OLEDs, in which the anode is made of a transparent conducting organic compound, e.g., doped polyaniline (see Fig. 1.2),44 or poly(3,4-ethylene dioxy-2,4-thiophene) (PEDOT)-polystyrene sulfonate (PEDOT-PSS) (see Fig. 1,2)45 deposited on a suitable plastic, e.g., transparency plastic, have also been reported. 

Michira, I. N. Klink, M. R.O. Akinyeye Somerset, V. M. Sekota Al-Ahmed, A. P.G.L. Baker Iwuoha, E. I. In Recent advances in analytical electrochemistry Anthracene sulfonic acid-doped polyanilines electrodynamics and application as amperometric peroxide biosensor Kenneth, O. Ed. Chapter 5 Transworld Research Network Karala India, 2007 Vol., pp. 137. 

Fig. 13 Example of an electrically conducting LLC acid-doped polyaniline salt complex that forms an L phase. Reproduced with permission from [97]. 2002 by Taylor and Francis...

Water can be removed from methanol by a membrane of polyvinyl alcohol cross-linked with polyacrylic acid, with a separation factor of 465.204 A polymeric hydrazone of 2,6-pyridinedialdehyde has been used to dehydrate azeotropes of water with n- and /-propyl alcohol, s- and tort butyl alcohol, and tetrahydrofuran.205 The Clostridium acetobutylicum which is used to produce 1-butanol, is inhibited by it. Pervaporation through a poly(dimethyl-siloxane) membrane filled with cyclodextrins, zeolites, or oleyl alcohol kept the concentration in the broth lower than 1% and removed the inhibition.206 Acetic acid can be dehydrated with separation factors of 807 for poly(4-methyl-l-pentene) grafted with 4-vinylpyridine,207 150 for polyvinyl alcohol cross-linked with glutaraldehyde,208 more than 1300 for a doped polyaniline film (4.1 g/m2h),209 125 for a nylon-polyacrylic acid membrane (5400 g/m2h), and 72 for a polysulfone.210 Pyridine can be dehydrated with a membrane of a copolymer of acrylonitrile and 4-styrenesulfonic acid to give more than 99% pyridine.211 A hydrophobic silicone rubber membrane removes acetone selectively from water. A hydrophilic cross-linked polyvinyl alcohol membrane removes water selectively from acetone. Both are more selective than distillation.212... 

Figure 8.1. Thickness dependence of total Shielding Efficiency (SE,) of highly conducting polymers measured at 6.5 GHz (from [23c]) sample A stretched heavily iodine doped Tsukamoto polyacetylene (dotted line is obtained by using calculation of Se, with approximated values of a absorption coefficient and n) sample B unstretched heavily iodine doped Tsukamoto polyacetylene sample C camphor sulphonic acid doped polyaniline in m-cresol solvent sample D PFe doped polypyrrole sample E TSO doped polypyrrole Inset comparison of (microwave conductivity), c, and tan 6, Reprinted from ref. 23c with permission. Copyright American Institute of Physics.

Moreover, the metallic nature already observed in the case of polyacetylene [58,59] has been found in other polymers such as camphor sulphonic acid (CSA) doped polyaniline [60] or polypyrrole [61]. In these materials, a negative dielectric constant [53], and a cross-over from the metallic to the non-metallic state between 20 and 50 K has been revealed in the case of polyaniline [62]. Polyorthotoluidine fibres doped with CSA in m cresol exhibit similar behaviour [63-65], PFg doped polypyrrole also exhibits such behaviour and the Drude model has been used for a description of dielectric constant evolution up to the infrared range [66], This model has also been applied to polyaniline [67],... 

Figure 8.22. Comparison between experimental points ( ) and calculated curves (—) of c and e" for HCI doped polyaniline (ClfN = 0.158).

It is equally possible to visualise in another way, the differences in frequency behaviour of differently acid-doped polyaniline samples (Figure 8.27). Indeed, at a given level of e", the more important the counter ion size, the higher the frequency dependence (increase in S"). 

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